On definite Proportions. 173 
amounted to 48°7 per cent.: so that the products obtained 
weighed 9 per cent. more than the salt employed. This partly 
depends on the quantity of water of crystallization in the sul- 
phate of ammonia, and partly on that of the new double salt. 
In order to determine more correctly the composition of this 
subsalt, I dissolved 5 grammes of it in water, saturated the so- 
lution with muriatic acid, and precipitated the sulphuric acid 
with muriate of baryta. The precipitate, when washed and 
ignited, weighed in one experiment 4°685, and in another 4:7 
gr., answering to 32°25 per cent. of sulphuric acid. 
The superfluous baryta was thrown down with sulphate of 
, soda, and then the filtered solution mixed with carbonate of 
potass, and evaporated to dryness. The mass, when redissolved, 
had an excess of potass, and afforded a greenish solution; the 
potass was nearly saturated with muriatic acid, and the carbonate 
of copper, received on a filter, washed, dried, and ignited. The 
liquid, still a little alkaline, exhibited by means of sulphuretted 
hydrogen a small residuum of copper, which being separately 
ignited, and weighed with the rest, made tegether 1-7 er., or 34 
per cent. of oxide of copper. We therefore find in this salt the 
+, ame proportion between the acid and the oxide of copper, as in 
the neutral sulphate, and its properties as a subsalt ave wholly 
dependent on the ammonia. ut does the salt contain a quan- 
tity of ammonia capable alone of forining a neutral salt with the 
same quantity of sulphuric acid? I was at first persuaded that 
it did. 
I mixed, in order to examine this, 5 grammes of the same salt 
in a small glass retort, with finely levigated lime, and decomposed 
it exactly in the same manner as I have related respecting the 
sulphate of ammonia. The little apparatus had lost 1-32 
grammes, consequently the salt must have afforded 26:4 per 
cent. of ammonia, The 7:35 per cent. wanting must have beer 
water, so that the cuprum ammoniatum is thus constituted: 
Sulphuric acid .... 32°25 
Oxide of copper .. 34:00 
Ammonia........ 26°40 
Watek Baniahia iiss 46." 7-35 
This quantity of the oxide of copper contains 6°68, and the 
water 6°5 parts of oxygen, so that the oxide and the water are in 
«the same proportion in this salt as in the subsulphate of the oxide 
of copper. ‘The ammonia contains 12-424 parts of oxygen, or 
about twice as much as the other component parts ; for'we have 
seen that it is impossible to exhibit this salt in a state of dryness, 
without depriving it of a little of its alkali; so that the quantity 
must appear too small in this analysis. 
It is evident that the two bases taken together here contain 
; an 
a % 
